Emergency room doctors often have only a few minutes to determine which patients are in need of a blood transfusion.

But currently doctors have no direct method to assess the health of one of the most critical component of the blood: platelets. These tiny blood cells play a huge role in helping blood clot after an injury.

Now researchers at the ÌìÃÀÓ°ÊÓ´«Ã½ have created a novel system that can measure platelet function within two minutes and can help doctors determine which trauma patients might need a blood transfusion upon being admitted to a hospital. The team March 13 in Nature Communications.

“Our system requires a tiny amount of blood to look at how healthy platelets are in real time,” said co-corresponding author , an associate professor in the UW Department of Mechanical Engineering. “We found that platelet function is a far better measure of platelet health and whether a trauma patient will need a blood transfusion than current methods.”

Platelets are the first responders to any sort of damage to blood vessels.

“They act as a sort of instant patch,” Sniadecki said. “They become activated and stick to the damage, and then they rapidly change their shape to stretch and reach out for more of the wound surface or other platelets. Then they begin to come back together to compact and add strength to a clot.”

In patients who’ve experienced trauma, however, platelets can lose the ability to do their jobs, including becoming less able to apply the forces needed to stop bleeding.

“When trauma patients come into the ER, we use a variety of methods to estimate their risk of bleeding, but none of these tests tells us specifically about platelet strength,” said co-corresponding author , an associate professor of emergency medicine at the UW School of Medicine.

White, Sniadecki and their team designed a microfluidic device that measures platelet forces in real time. First, the researchers inject a blood sample into the device. As the blood flows through it, the cells hit an obstacle course: tiny blocks and posts jutting up from the base of the device. This activates the platelets. They feel a massive force when they flow over the blocks, and then the surface of both the blocks and the posts are coated with a platelet-activating molecule.

“The block and post structures act like a mini wound surface,” said lead author , who conducted this research as a mechanical engineering doctoral student at the UW. “The platelets attach between the block and post, and they start to snowball. They aggregate to form a miniature plug that then begins to contract and pull the post toward the block. Based on how far the post moves, we can determine how functional the platelets are.”

Sniadecki’s lab has used to measure cell forces, but this is the first time that blocks have been added to the mix. Without the blocks, the platelets didn’t stick to the posts.

“As the platelets whip around the block, they are forced to change direction rapidly, and that activates the platelets,” Ting said.

To test their device, the researchers recruited participants from Harborview Medical Center. After providing informed consent, 93 trauma patients and 10 healthy participants had their blood sampled when they arrived at the center.

The results showed a significant difference between the healthy participants’ blood and that of the trauma patients. Trauma patients’ platelets had decreased forces compared to healthy participants’ platelets. Of the trauma patients, 17 required a blood transfusion during their first 24 hours in the hospital. These patients also had the lowest platelet forces compared to the trauma patients who didn’t receive a transfusion.

Sometimes trauma patients have fewer platelets, so one current test in the ER is to count the number of platelets. But when the researchers looked at platelet count for this study, all blood samples — including those from healthy participants — had a comparable number of platelets.

“It’s a big deal not just knowing how many platelets are in the blood but knowing how well they’re actually functioning,” White said. “It’s not always obvious which patients will need a blood transfusion, and a device like this can really help us make decisions quickly.”

Currently the team is working to make the device more user-friendly.

“It’s still a prototype where you have to have some training in how to operate it to get a reading,” said Ting, who is now director of research and development at , the company that spun out from this research. “Our goal is to make it user-friendly and comparable to a blood sugar monitoring device where people deposit blood samples on a strip and put it into the reader. Then the reader just takes care of it.”

The team also hopes the device will be useful for measuring platelet strength in other areas of medicine, such as measuring how blood-thinning medications like aspirin or Plavix affect different patients or helping neurosurgeons monitor patients for bleeding complications during surgery.

Co-authors include , a senior engineer at BD Biosciences who conducted this research while a UW mechanical engineering doctoral student; , a mechanical engineering doctoral student; Annie Smith, who was a mechanical engineering research scientist but is now a research scientist at Stasys; , the director of operations at Stasys who completed this work as a mechanical engineering postdoctoral fellow; , a scientist at the Seattle Cancer Care Alliance who conducted this research as a research scientist at UW Medicine; , an assistant professor of emergency medicine at Harborview Medical Center; Xu Wang, a UW emergency medicine research scientist; and , a biostatistics research scientist. The microfluidics cards used in this study were made at the  at UW.

This research was funded by the Defense Advanced Research Projects Agency Young Faculty Award, the Coulter Foundation Translational Research Award, grants from the Life Science Discovery Fund, the Combined Funding Initiative, ÌìÃÀÓ°ÊÓ´«Ã½ CoMotion, the National Science Foundation and the National Institutes of Health.

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For more information, contact Sniadecki at nsniadec@uw.edu.

Grant numbers: N66001-11-1-4129, LSDF-7434512, CMMI-1402673, UL1TR000423, KL2TR000421, EB001650

During the next month, the ÌìÃÀÓ°ÊÓ´«Ã½’s College of Engineering will feature faculty researchers in engineering and medicine who are improving cardiac medical care with new technologies. All lectures are free and open to the public.

The series kicks off on Wednesday (Oct. 15) in 120 Kane Hall with “.” , a UW professor of pathology, cardiology and bioengineering, will share how his team is using engineering, stem cells and medicine to regenerate heart muscle. This could help rebuild muscle tissue after a heart attack.

On Tuesday, Nov. 4, in 120 Kane Hall, speakers will talk about the biomechanics of cells in the cardiovascular system. We depend on active cells that can create blood clots to prevent blood loss in an injury or pump blood throughout our bodies when we exercise. UW engineers and physicians are studying cell biomechanics to try to improve blood clotting to help with healing in traumatic injuries.

, an associate professor of mechanical engineering and adjunct professor of bioengineering, and , an assistant professor of emergency medicine and adjunct assistant professor of bioengineering, will present “.”

Finally, on Tuesday, Nov. 18, the focus will be on new ways to power implantable devices such as pacemakers. Using battery packs and even cables to run these electronics is cumbersome, and engineers are discovering ways to wirelessly deliver power to devices by harvesting ambient cellular phone and TV signals from the air. , an associate professor of computer science and engineering and of electrical engineering, will explain his team’s work in this field in “.”

All lectures are free and start at 7 p.m. Advance registration, either or by calling 206-543-0540, is required. All lectures will be broadcast at a later date on .

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People around the world are doing all this and more with a tiny, durable magnification lens built by an enterprising ÌìÃÀÓ°ÊÓ´«Ã½ undergraduate student.

The , developed by UW mechanical engineering alumnus Thomas Larson (’13), can turn any smartphone or tablet computer into a hand-held microscope. The soft, pliable lens sticks to a device’s camera without any adhesive or glue and makes it possible to see things magnified dozens of times on the screen.

“A microscope is a tool you can do thousands of different things with and by making it cheaper, portable and able to take pictures, you open so many different possibilities that weren’t available before,” Larson said.

Larson completed his undergraduate degree in 2013 and formed his own company based in Olympia, Wash. After the initial success this winter of his first model that magnifies by 15 times, he is creating a new lens that will magnify up to 150 times. (Standard laboratory microscopes usually magnify between 50 and 400 times.)

The lens is about the size of a button and comes in its own carrying case. Users stick it flat onto a smartphone camera lens, turn on an external light source such as a lamp, then run the device in camera mode. Moving the device closer or farther from the object brings it into focus.

Several other products exist that can adapt a smartphone to be used as a microscope, but they are significantly more expensive, and the attachments are heavy or require permanent adhesives.

Larson developed his smartphone lens while working in the lab of , a UW associate professor of mechanical engineering. The lab needed a miniaturized lens that could work with a cellphone as a microscope, and Larson took on the project. The lens he developed is now as powerful as the research microscopes used in the lab, Sniadecki said.

Larson decided to commercialize his product and participated in the 2013 UW Business Plan Competition, where his team placed in the top 16. Funding trickled in through various awards and scholarships that helped with early prototypes and advertising materials, but the project’s potential was still iffy.

“Thomas did something that was truly unique — he dove right into the technology and the entrepreneurship,” Sniadecki said. “Most mechanical engineers have jobs lined up after graduation, but Thomas chose to forego the ‘safe’ path and plunged himself into risky water.”

After graduating last summer, Larson ran a Kickstarter campaign for the 15X microscope lens, and more than 5,000 people signed up. For the new graduate who was still looking for a job and living with his parents in Olympia, this was a sure sign of success.

“It all just happened,” he said. “Working at the UW helped me figure out the technical and business problems, but the Kickstarter proved this technology is something people wanted.”

Larson shipped orders to people around the world who needed a microscope they could use in the field or in classrooms where expensive microscopes are in short supply. Now, he is creating the 150X lens, which will be available this summer. He manufactures the lenses at his lab space in Olympia and is working with an optical mold-making company to design more sophisticated optics for this new model.

Larson said he hopes the new design will be useful in disease diagnosis overseas, and in the increasing number of classrooms where iPads are the norm but microscopes still come at a premium. He is working with a global health physician to try to test the microscope at a clinic in Kenya, and he’s getting feedback from teachers on what they need for their students.

“I’m hoping this microscope can make a difference,” Larson said. “If I can just make it available, the right people and experts in the field can see its usefulness and take it from there.”

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For more information, contact Larson at thomas@microphonelens.com or 360-250-6894.